Rotary plow for the removal of snow



y 19, 1953 F. F. WALLACK 2,638,691

ROTARY PLOW FOR THE REMOVAL OF SNOW Filed June 8, 1950 2 Sheeis-Sheet 1Fig-3 A/wrmfy M 9, 1953 F. F. WALLACK 2,638,691

ROTARY PLOW FOR THE REMOVAL OF SNOW Filed June 8, 1950 2 Sheets-Sheet :2

INVEN TOR.

Patented May 19, 1953 Franz Ferdinand Wallack, Bruck an derGiockners'trasse, Austria, assignor to Grossglockner Ho'chalpenstrasscn"Aktiengcselischaft, burg, Austria, a corporation of Austria ApiplieationJune 8, 1950, Serial No. 166,834

In Austria September 13, 1947 8 Claims. (01. 37 -43) The presentinvention relates toia' rotary snow plow or the kind having snow-cuttingdevice's arranged in front of a throw wheel designed for discharging thesnow from the areato be cleared. A. Show blow of this kind isparticularly "suitable for the removal of old snow, for. example hard ofsubstantial thickness and delivering such cutoff laminarbodies of snowto the throw wheel in such manner as to avoid packing, sudden impactsand abrupt changes'i'n the direction of movement of the snow. Theefiiciency and reliability of operation of the snow plow are therebymaterially increased.

Another object of the invention is to provide a rotary snow plowoftheikind indicated which will make ossible the removal or a mass of snowhaving a height greater than the diameter of the snow-relnoval cylinderwith which the plow is provided.

A further object of the invention is to provide a snow plow having asnow-removal cylinder that is readily adaptable to different operatingconditionsso as to provide maximum ehiciency of operation under allconditions.

Other objects and advantages of the invention will appear from thefollowing description and claims in conjunction with the accompanyingdrawings, in which: i i

l. is a side elevation, partly in longitudinal section, of a snow'plowin accordance with the invention mounted on-a-self-propelled vehicle.

Fig. 2 is a plan view of the snow plomwith portions removed in order toillustrate the construction more clearly. v

3 is an enlarged cross sectional view of one of the snow-romovalcylinders.

4 is a cross section on a still larger scale of a guide blade ofthesnow-removal cylinder embodying a preferred construction.

= of longitudinally extending radial projections to blades have convexsnow engaging surfaces, be-

Figs. 6 and 7 are diagrammatic cross sections of the snow-removalcylinder illustrating its milliseconds at a iotary speed t merevolutions per minute.

Figs. 10 and 11 are diagrammatic cross sections showing modifiedembodiments of the snow plow in which the snow removal cylinder isrotated in the opposite direction.

In the embodiment shown in Fig. 1, the snow plow is mounted on the framei of a track-type vehicle having tracks 2 driven by a motor 3 throughgearing I. It 'will be understood, however, that the snow plow may,instead, be mounted on a wheeled vehicle or locomotive.

A shaft 5 leads from the gearing 4 to a transmission 6 which has adriving shaft 1 for driving through beveled gearing 8 the two shafts 9of two snow-removal cylinders H arranged symmetrisally with respect tothe central plane of the snow plow. The shafts 9 extend transversely tothe direction ofmov'ement of the snow plow and are carried by the plowframe l0. Each. of the snow-removal cylinders comprises a pair of spaceddiscs 18 which are carried, and. rotate with, the shaft 9 and aplurality of cutting blades l2 extending betweenethe discs 18 anddisposed at the peripheries of said discs. It is preferable that thenumber of cutting blades be small. three blades being illustrated in thedrawings. The snow-removal cylinder also comprises a correspondingnumber of guide blades I3 having inner edges M pivotally' connected to arotary core member I5, the pivotal connections being indicated at Hi.The core portion 15 has a plurality which the guide blades 13 arepivotally connested. Between these projections, there are troughs havingconcavely curved bottomsthat lie as close as ossible to the shaft 9. Theguide ing of somewhat airfoil cross section. The convex surfaces ofthesuide blades merge smoothly into the concavely curved bottoms of thetroughs of the core member Is to provide a smoothh curved surfaceextending. continuously from the outer edge of one guide blade to thatof the next.

"The outer edges of the guide blades are shown as carrying metal stripsI! which maybe moved outwardly or inwardly to adapt the guide blades 13to the setting of the cutting blades 42.

The core member I5 is rotatably supported by the shaft 9. series ofholes [9 (Fig. 3) are provided in. theside discs ii of the snow rernovalcylinders l l at the ends of the core member and bolts can be stuckthrough these holes and into alignedholes in the projecting portions ofi the core memberjto adjust the angular position of the'core member i l5relative to the side discs b8 and thus relative to the cutter bladesiii. The side discs l5 'arealso provided with series of 3 holes 2ll-at agreater distance from the axis of the cylinder-and bolts may be stuckthrough the latter holes to alter the position of the guide blades I3relativeto the side discs I8 and the core member 'l2 and secure the.guide blades in selected position.

In the embodiment of Figs. 1 to 9, the snowremoval cylinders areintended to rotate in the direction of the arrow 2| so that the cuttingblades I2 cut into the snow durin their downward movement. The cuttingedges of the blades I2 are shown as being straight and approximatelyparallel to the axis of rotation of the snow-removal cylinders. Theradius m (Fig. 3) of the outermost edges of the guide blades I3 issmaller than the radius 1'1 of the cylinder defined by the cutting edgesof the blades I2as the cylinder revolvesso that the snow engages theguide blades only after it has been cut off by the cutting blades. I

' Directly behind the snow-removal cylinders I I, there are providedthrow wheels having their axes approximately parallel to the directionof movement of the snow plow and hence approximately perpendicular tothe axis of the snow-removal cylinders. The sum of the diameters of thethrow wheels is approximately equal to the combined lengths of thesnow-removal cylinders, so that the snow delivered to the throw wheelsby the snow-removal cylinders is not crowded together and compacted-asoccurs with helical or screwtype snow-removal devices-and hence movesfreely without clogging,

While the throw wheels may, if desired, be driven from the same motor 3through suitable gearing, it has been preferable to provide a separatemotor for this purpose. The embodiment illustrated in the drawings isaccordingly shown as having an additional motor 22 which drives thethrow wheels through a shaft 23, bevel gearing 24, shafts 25 and twobevel gear assemblies 26.

A shaft 21 extends from. each of the bevel gear assemblies 26 to atransmission 28 driving the shaft 29 of the respective throw wheels. calhub 30 is mounted on the shaft 29 and carries a plurality of throwblades 3|. Each throw wheel has a casing 32 with an inlet opening 33 anddischarge passage 34.

The mode of operation of the snow plow will now be described. When thesnow-removal cylinder II is rotated in the direction of the arrow 2|(Fig. 3), a laminar body of snow 4| is cut oh? by each cutting blade I2.The cutting action occurs in the sector a in Fig. 8. The laminar body ofsnow that has been severed enters the interior of the snow-removalcylinder I I where, being left to itself, it curls in as a result of theinfluence of gravity and the velocity imparted to it by the cuttingblade I2. This curling in process is theoretically illustrated insuccessive phases in Fig. 9. The numberof the cutting blades I2 andtheir inclination a. to the tangent of the circumference of the sidediscs I8 are so chosen that,

in the spaces 42 between successive guide blades I3, the cut-off laminarbodes of snow 4| will lag behind the cutting edges of the blades I2 andthe outside surface of the curled in body encloses the smallest possiblevolume. As the cylinder I continues to turn, the curled in laminar body4| of snow meets a guide blade I3 in the closest proximity to the shaft9'. For this purpose, the cutting blades are disposed closer to theguide blades in front of them than to the guide blades behind them, sothat the laminar portions of snow cut off by the cutting blades curl intoward the center A coni- 4 of the snow-removal cylinder before beingengaged by the guide blades I3. Owing to the special shape of the guideblades I3, the integrity of the curled in laminar bodies 4| of snow ispreserved'as far as possible.- the laminar bodies 4| of snow beinreceived by the guide blades I3 as gently as possible without impact andWithout abrupt change in the direction of movement of the snow. By thusavoiding impact of the guide blades I3 with the laminar bodies of snow,it is possible to avoid objectionable packing of the snow. Moreover, theamount of power required for driving the snow-removal cylinders isthereby appreciably decreased with corresponding increase in efficiencyof operation. The bottoms of the troughs formed in the core member ofthe snow-removal cylinder are arranged as close as possible to the axisof the cylinder and for this purpose the shaft 9 is preferably made assmall as permitted by structural requirements. The laminar body. of snowis now contained in the space or chamber 42 formed by the guide blades I3 and by an imaginary surface connecting the outer most edges ofsuccessive guide blades. The guide blades I3 receive the snow close tothe shaft 9 and convey it at increased velocity toward the circumferenceof the snow-removal cylinder (sector b in Fig. 8) and thence into theinlet opening 33 of the throw wheel 3|], 3| (sector 0 in Fig. 8). Duringthe succeeding sector (1 in Fig. 8, the cutting blades and guide bladesare idle, whereupon they again reach sector a and the cycle is repeated.The snow delivered into the throw wheel 30, 3| is discharged a greateror lesser distance, as may be required by the nature of the area beingcleared. In Figs. 7, l0 and 11, the throw wheel 3t, 3| is shown onlydiagrammatically,

' The position of the metal strips I! (Fig. 4) o the outer edges of theguide blades I3 can be ad* justed according to the setting of thecutting blades I2. It is thereby possible to prevent portions of thelaminar body 4| from one cutting blade from entering a subsequentchamber 42 where they would interfere with the movement of the laminarbody of snow contained therein. These metal strips II are adjustedaccording to the thickness of the laminar body 4| of snow so that theportion of the guide surface alon which said laminar body travels alwayshas the largest effective surface for the deflection of the body of snowtoward the throw wheel.

The snow plow in accordance with the invention may also be adapted tovarying conditions of operation, such as variations in the condition ofthe snow and/or in the working speed, by altering the angularrelationship between the cutting edges of the cutting blades I2 and theinnermost portions of the troughs formed between the guide blades I3. Itis also possible to adjust the angle a at which the cutting blades I2are set to a plane tangential to the side discs I8 and to adjust theguide blades I3 and the movable corernember I5 in order to adjust theform of the guide surfaces to the particular snow conditions that areencountered.

In the rotary plow according to the present invention, the snow isalways deflected in such a manner that the cut off laminar body 4| ofsnow is discharged in its entirety in a substantially frictionlessmovement of the snow-removal cylinder.

Because the laminar body of snow can follow its natural curling tendencywith perfect freedom and without any interference, any clogging ofpassages is reliably prevented. Moreover, the

' either by sliding or folding.

in providing a guide surface that is adapted to receive a laminar bodyof snow cut off by a cutting member after said laminar body has beenallowed to curl in without any interference may be utilized for varioustypes of snow removal devices. A snow plow in accordance with theinvention may "comprise one or more snow-removal cylinders rotating inany desired direction and one or more 'throw wheels and may, if desired,be combined 'with other removal elements which are known per se.

As far as the basic idea of the invention is concerned, it makes nodifference whether the snow is cut oil from top to bottom or from bottomto top. The latter embodiment, however, has special advantages becausethe snow, while being conveyed from the snow-removal cylinder to thethrow wheel casing is subject only to its own gravity and requires noadditional lifting force for its conveyance. In this embodiment, the

throw wheel casing may be located at a greater height above the roadbed,so that it cannot be blocked by snow. This embodiment also exeludes anyclogging of the passage between the snow-removal drum and the throwwheel, particularly because the movement of the snow into i the throwwheel is assisted by its own gravity.

Figs. and 11 show arrangements in which the snow-removal cylinder Hrotates in the opposite direction from that of the embodiment shown inFigs. 1 to 9, so thatin the free space 43 adjacent to the upper portionof the snowremoval cylinder, the movement of the snow is subject to theinfluence of gravity so that the snowremoval cylinder 1 l is emptiedfrom top to bottom. When the snow-removal cylinder is rotated in thedirection of the arrow in Figs. 10 and 11," anupwardly projectingguidesurface 35 is preferably provided at the front edge of the casing 32that encloses thethrow wheel and the rearward portion of thesnow-removal cylinder.

In order to prevent the discharge of snow dust which would blur the viewof the operator and to permit the discharge of hard bodies, a covermember 36 (Fig. 11) may be provided over the front portion of thecircumference of the snow-removal cylinder. This cover member 36 can bemoved back in the direction of rotation, In this case, the guide surface35 is attached to the front edge of the movable cover 36 and may, ifdesired, be made resilient. I i

Fig. 10 shows that the axis of the throw wheel 38, 3| may be higher thanthe axis of the snowremoval cylinder by a distance Bl. It is therebypossible to provide greater clearance between the casing 32 of the throwwheeland the. road.

,Figs. 1 and '7 illustrate that the snow-removal cylinders i 1, togetherwith the throw wheels30, 3|, may be swingably suspended on the vehicleframe so as to swing about a transverse shaft 38. The shaft 38 may, forexample, be the rear axle of the track drive. The raising and loweringof the snow-removal cylinders is effectedby means of hydraulic cylinders39 which are operated by suitable means indicated schematically at. Asthe snow plow travels forwardly, the unit comprising the snow-removalcylinders and throw wheels, together with their respective casings,isswung up and down by means. of the hydraulic cylinders 39, so that itis possible to remove a mass of snow the height of which is larger thanthe diameter of the snow-removal cylinders. It is not necessary,however, that the throw wheels be arranged to swing together with thesnow-removal cylinders since it is sufficient to raise and lower thesnow-removal cylinders H alone. The swingable suspension isof specialadvantage when the snow is conveyed from bottom to top, as illustratedin Figs. 10 and 11, because, in that case, thesnow plow has no tendencyto climb up on the snow.

What I claimis:

1. In a rotary snow plow; a rotatable throw wheel and a snow removalcylinder positioned to dischargesnow into said throw wheel, said snowremoval cylinder comprising a rotatable shaft, a plurality of cuttingblades carried by and revolving with said shaft, the cutting edges ofsaid blades extending longitudinally of said cylinder and defining acylindrical surface as the shaft revolves, a core portion rotatable withsaid shaft and having a plurality of longitudinally extending radialprojections forming between them troughs having concavely curved bottomsclose to said shaft, and guide blades projecting radially outwardly fromsaid projections, the radius of said guide blades measured from the axisof said shaft being substantially less than that of the cutting edges ofthe cutting blades, said guide blades having convex snow-engagingsurfaces merging smoothly into the concave surfaces of said trough ofsaid core portion to provide a smoothly curved surface from the outeredge of one guide blade to the next and said cutting blades beingdisposed closer to the guide blades in front of them than to the guideblades behind them, so that snow cut off by said cutting blades curlsinwardlytoward said shaft and'is directed to the throw wheel by saidguide blades without abrupt change of direction;

2. In a rotary snow plow, a snow removal cyl- 'inder comprising arotatable shaft, a plurality of spaced discs revolving with said shaft,a plurality of cutting blades extending between said discs and disposedat the peripheries of said discs, the cutting edges of said bladesdefining a cylindrical surface as the shaft revolves, a core portionrotatable with said shaft and disposed betweensaid discs, saidcoreportion having a plurality of longitudinally extending radialprojections forming between them troughs having concavely curved bottomsclose to said shaft, and guide blades projecting radially outwardly fromsaid projections, the radius of said guide blades measured from the axisof said shaft being substantially less than that of the cutting edges ofthe cutting blades, said guide blades having convex snow-engagingsurfaces merging smoothly into the cancave trough surfaces of saidcoreportion to provide a smoothly curved surface from the outer edge of oneguide blade to the next and said cutting blades being disposed closer tothe guide blades ahead of them than to the guide blades behind them sothat snow cut off by said cutting blades curls inwardly to the bottomsof said troughs near said shaft and is then'directed rearwardly by saidguideblades without abrupt 1 change of direction. i 1

3. In a rotary snow plow, a snow removal cylinder comprising a rotatableshaft; a plurality of'spaced discs revolving with said shaft, aplurality of cutting blades extending between said discs and disposed atthe peripheries of said discs, the cutting edges of said blades defininga cylindrical surface as the shaft revolves, a core member rotatablewithv said shaft and disposed be tween said discs, said core memberhaving a plurality of longitudinally extending radial projectionsforming between them troughs having concavely curved bottoms close tosaid shaft, guide blades projecting radially outwardly from saidprojections and pivotally connected thereto so as to swing about theirpivots to a plurality of different angular positions relative to saidshaft and discs, and means for holding said guide blades in selectedposition, the radius of said blades measured from the axis of said shaftbeing substantially less than that of the cutting edges of the cuttingblades, said guide blades having surfaces merging smoothly into thetrough surfaces of said core member to provide a smoothly curved surfacefrom the outer edge of one guide blade to the next.

4. In a rotary snow plow, a snow removal cylinder comprising a rotatableshaft, a plurality of cutting blades carried by and revolving with saidshaft, the cutting edges of said blades extending longitudinally of saidcylinder and defining a. cylindrical surface as the shaft revolves, acore portion rotatable with said shaft and having a plurality oflongitudinally extending radial projections forming between them troughshaving concavely curved bottoms close to said shaft, guide bladesprojecting radially outwardly from said projections and having surfacesmerging smoothly into the trough surfaces of said core portion toprovide a smoothly curved surface from the outer edge of one guide bladeto the next, the radius of said guide blades measured from the axis ofsaid shaft being substantially less than that of the cutting edges ofthe cutting blades, movable metal strips extending along the outermostedges of the guide blades, said strips being movable radially oftheguide blades and means for securing said strips in selected positionrelative to the guide blades.

i 5. In a rotary snow plow, a snow removal cylinder comprising arotatable shaft, three cutting blades carried by and revolving with saidshaft, the cutting edges of said blades extending longitudinally of saidcylinder and defining a cylindrical surface as the shaft revolves, acore portion rotatable with said shaft and having three longitudinallyextending radial projections forming between them troughs havingconcavely curved bottoms close to said shaft, guide blades projectingradially outwardly from said projections, the radius of said bladesmeasured from the axis of said shaft being less than that of the.

cutting edges of the cutting blades, said guide blades being disposedbetween successive ones of said cutting blades and having convexsnowengaging surfaces merging smoothly into the trough surfaces of saidcore portion and to provide a smoothly curved surface from the outeredge of one guide blade to the next and said cutting blades beingdisposed at least 60 ahead of the guide blades behind them so thatlaminar portions of snow cut off by said cutting blades curl inwardly tothe bottoms of said troughs and are directed rearwardly by said guideblades without abrupt change of direction. I 6. In a rotary snow plow, asnow-removal cyl inder comprising a rotatable shaft, a plurality of tosaid shaft and discs, said core member having a plurality oflongitudinally extending radial projections forming between them troughshaving concavely curved bottoms close to said shaft and guide bladesprojecting radially outwardly from said projections, the radius of saidguide blades measured from the axis of said shaft being substantiallyless than that of the cutting edges of the cutting blades, said guideblades having surfaces merging smoothly into the trough surfaces of saidcore member to provide a smoothly curved surface from the outer edge ofone guide blade to the next.

7. In a rotary snow plow, a snow-removal cylinder comprising a rotatableshaft, a plurality of spaced discs revolving with said shaft, aplurality of cutting blades extending between said discs and disposed atthe peripheries of said discs, the cutting edges of said blades defininga cylindrical surface as the shaft and discs revolve, a

core member rotatable relative to said discs and disposed between saiddiscs, means for holding said core member in selected angular positionrelative to said discs, said core member having a plurality oflongitudinally extending radial projections forming between them troughshaving concavely curved bottoms close to said shaft, guide bladesprojecting radially outwardly from said projections and pivotallyconnected thereto so as to swing about their pivots to a plurality ofdifferent angular positions relative to said discs, and means forholding said guide blades in selected position, the radius of saidblades measured from the axis of said shaft being substantially lessthan that of the cutting edges of the cutting blades, said guide bladeshaving surfaces merging smoothly into the trough surfaces of said coremember to provide a smoothly curved surface from the outer edge of oneguide blade to the next.

8. In a rotary snow plow, a rotatable throw wheel having its axisapproximately parallel to the direction of movement of the snow plow anda snow-removal cylinder positioned in front of said throw wheel, saidsnow-removal cylinder comprising a rotatable shaft substantiallyperpendicular to the axis of said throw wheel, a plurality of spaceddiscs carried by and rotating with said shaft, a plurality of cuttingblades extending between said discs and disposed at the peripheries ofsaid discs, said blades having straight cutting edges substantiallyparallel to said shaft, a core portion rotatable with said shaft anddisposed between said discs, said core portion having a plurality oflongitudinally extending radial projections forming between them troughshaving concavely curved bottoms close to said shaft, and straight guideblades projecting radially outwardly from said projections, the outeredges of said guide blades being substantially parallel to said shaftand nearer said shaft than said cutting edges, said guide blades havingsmooth surfaces that merge smoothly into the concave trough surfaces ofsaid core to provide a smoothly curved surface from the outer edge ofone guide blade to the next, and said cutting blades being disposedcloser to the guide blades in front of them than to the guide bladesbehind them, so that snow cut off by said cutting blades curls inwardlytoward said shaft and is directed rearwardly to the throw wheel by saidguide 5 blades without abrupt change of direction and withoutcompacting, said snow-removal cylinder being rotated in a direction suchthat the cutting blades out in an upward direction.

FRANZ FERDINAND WALLACK. 10

References Cited in the file Of this patent UNITED STATES PATENTS NameDate Number Number Name Date Gehl Aug, 8, 1939 Voorderman Apr. 23, 1940Jensen Dec. 17, 1940 Venable Oct. 23, 1945 Wandscheer Oct. 30, 1945Eliot Apr. 22, 1947 Inksetter Aug. 26, 1947 FOREIGN PATENTS Country DateAustria Nov. 10, 1937 Switzerland July 1, 1947

